1. Field of the Invention
The present invention relates to a connector.
2. Description of the Related Art
Blow-by gas is gas that has leaked from the space between a cylinder of an engine and the piston. A blow-by gas collection piping is mounted on a vehicle and has a plurality of tubes that connect an engine and an air intake duct to each other. Thus, the blow-by gas collection piping feeds the blow-by gas back to the air intake duct to prevent the blow-by gas from being discharged to the atmosphere. Maintenance of the vehicle may require the tubes to be disconnected from each other. A visual check then is performed to determine whether the tubes have been returned to their original positions.
However, the engine operates even if the tubes have not been returned to their original positions. In this case, the blow-by gas is discharged to the atmosphere by driving the engine without noticing that the tubes are disconnected from each other.
The present invention has been made in view of the above-described situation. Accordingly, it is an object of the present invention to provide a connector that can be utilized for a system to determine whether tubes have been disconnected from each other.
The connector of the present invention comprises two connector housings that can be fitted on each other, and that are immoveable in an axial direction of a pair of tubes. Metal terminal fittings accommodated separately in the respective connector housings are connected to each other by connecting the tubes to each other.
In this construction, the terminal fittings are connected to each other when the tubes are connected to each other. Conversely, the terminal fittings are disconnected from each other when the tubes are disconnected from each other. Thus, the connector can be utilized as part of a system to determine whether or not the tubes have been disconnected from each other, by detecting the connection state of the terminal fittings.
Preferably, several pairs of connector housings are connected in parallel with a detection circuit for detecting an electrical connection between the terminal fittings. Thus it is possible to detect instantly which of the housings has been disconnected.
At least one of the connector housings may have a rotatable ring through which a tube is inserted, and the connector housing is rotatable on the rotatable ring. Thus, irrespective of whether the tube twists , the connector housings can be moved to face each other connector housing, and it is easy to fit both connector housings on each other.
At least one of the connector housings may be integral with a joint that is installed on an end of a tube and removably installed on a mating tube. The joint has a double cylindrical wall. One cylindrical wall is fitted on an inner side of the tube, and the other is fitted an outer side thereof. A flexible clamping portion is provided by forming a slit on an outer cylindrical wall of the double cylindrical wall to deform a part of the outer cylindrical wall flexibly inward. A clamping ring is fit on the outer side of the double cylindrical wall and slides between a clamping position, at which the flexible clamping portion deforms flexibly inwardly, and a non-clamping position distant from the clamping position. A locking portion is formed on the double cylindrical wall to lock the clamping ring to the clamping position.
In this construction, the joint on the connector housing is mounted on a tube by inserting an end of the tube between the outer cylindrical wall of the double cylindrical wall and the inner cylindrical wall thereof. The clamping ring then is moved from the non-clamping position to the clamping position to lock the clamping ring to the locking portion. Consequently, the clamping ring flexes the flexible clamping portion inward and the flexible clamping portion clamps the tube. Thus, it is possible to prevent a slip-off of the tube, and the joint portion can be unremovably mounted on the tube by merely moving the clamping ring from the non-clamping position to the clamping position.
The connector housing may further comprise a temporary locking mechanism for locking the clamping ring to the non-clamping position. Thus, it is possible to prevent the operator from forgetting to mount the clamping ring on the joint and to prevent the operator from erroneously moving the clamping ring to the clamping position before installation of the tube.
The joint may have an insertion cylinder for connecting a tube to be fit in the double cylindrical wall with a mating tube. The joint may also comprise a seal ring for a mating tube. The seal ring may be fit on a peripheral surface of the insertion cylinder. The joint may further comprise a double cylindrical construction formed between a peripheral surface of the insertion cylinder and the rotatable ring that is removably mounted on the insertion cylinder such that the mating tube can be fit into the double cylindrical construction.